The ZippyClaws Birds in Nest Burrow is lined with crinkle paper and includes two Miniz filled with catnip. ZippyClaws Burrow toys promote mental stimulation and encourage interactive play for curious cats. Simply stuff the little critters into the burrow and let your cat work to paw, claw, bite, and tug them out. Once they have them out, you can put them back in again for another round of fun! This interactive toy comes with 1 nest burrow and 2 small catnip Miniz birds. Birds also have bells inside for added entertainment.